Friction draft gear



New. 22, 1927.

A. F. STUEBING FRICTION DRAFT GEAR Filed cm. 4, 1926 2 Sheets-Sheet l 6 6 7". flart fizzicw'zg New. 22, 1921. 1,649,871

A. F. STUEBING FRICTION DRAFT GEAR Filed 09 14, 1926 2 Sheets-Sheet 2 {4'1 5067 07"; W/er mh'gq Patented Nov. 22, 1927.

ALBERT I. STUEBIN G, 01? EAST ORANGE, NEW JERSEY, ASSIGNOR TO THE BRADFORD PATENTS CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

- FRICTION DRAFT GEAR.

Application filed. October 14, 1926. Serial No. 141,559.

My invention relates to draft gears employing friction and spring shock absorbing mechanism and particularly to gears employing intercalated members and has for one of its objects the provision of a gear of simple construction having high frictional resistance and relatively large return force.

Theinvention has, as another object, the procurement of substantially uniform distribution of pressure upon multiple friction surfaces without requiring accurate fitting of parts. Other objects and advantages are also present in the preferred embodiment of my invention shown by the accompany ing drawings in connection with suitable draft sills, coupler and yoke.

In the drawings, Fig. 1 is a sectional plan view on line 1-1 of Fig. 2; Fig. 2 is a sectional elevation on line 2-2 of Fig. 1; Fig. 3 is a view of a part of the structure appearing in Fig. 2, parts in changed posi tions; Fig. 4 is a sectional view on line 14 of Fig. 1; Fig. 5 is a sectional view on line 55 of Fig. 1; Fig. 6 is a perspective view of some of the cooperating parts in separated relation; and Fig. 7 is a perspective view of a. portion of the load-sustaining column member which enters into the construction.

The draft sills 1 of arailway car underframe are shown as also constituting the center sills, to the inner sides of which are fastened the outer draft lugs 2 and inner draft lugs 3. The draft gear, to be later described, is placed within the space enclosed by the draft lugs and sills. Extending around the draft gear and its follower 4. is a yoke 5 to which the coupler 6 is attached by a key 7 passing through the draft sills, coupler and yoke in accordance with well known practice. The yoke, draft gear and follower are supported by carrier 8 which is carried by and beneath the aforesaid sills. The draft gear is compressible by bufiing force exerteddirectly through the coupler and by pulling force exerted by the coupler through the aforesaid key and yoke.

In addition to the follower 4, the draft gear shown includes a spring housin 9, a friction housing 10, a wedge 11, inner friction blocks 12 cooperating with said wedge, normally stationary friction plates 13, outer friction blocks 14, an application spring 15, and a release spring 16. The spring and friction housings together constitute a loadsustaining column member. They may be made integral but are preferably formed as separate parts and held together by rivets 17.

The spring housing isshown in the form of an open ended box with two opposite straight horizontal and two opposite cylindrically curved side walls. Said housing or box has an inner closed end 18 which is extended and reinforced with wings 19 that contact with the inner draft lugs 3. Lugs 20 are provided "at-the outer and open end of the box-like spring housing 9 for attachment to the lugs 21 of the friction housing 10 by the rivets 17. The friction housmg is open at both ends and has opposite straight horizontal and opposite cylindrical- 1y curved side walls. The inner curved surfaces of the curved side walls of the friction housing 10 act as friction surfaces and cooperate with the outer and cylindrically curved surfaces of the outer friction blocks 14. The axes of each pair of engaging cylindrical surfaces are coincident, the two axes of both pairs of such surfaces converging toward the inner end of the gear. Ledges 22, 23 extend along the straight, horizontal sides of the friction housing and support the friction plates 13 that are nor- Igially stationary respecting the column memer. the outward movement of wedge 11, which has lugs 11' engageable therewith.

The inner friction blocks 12 are in contact with the inner faces of the normally stationary friction plates 13 and make contact at their inner ends with'the application spring 15. The outer ends of the inner friction blocks 12 do not extend out as far as the wedge 11 and the outer friction blocks 14. Each inner friction block 12 has a plane surface 12 inclined to the axis of the gear and on which the adjacent inclined face of wedge 11 bears. When the gear is in release position, this wedge is held in place by the pressure of, application spring 15 actin thereon through the inner friction bloc s 12 to engage the lugs 11 with ledge 23. The a plication spring 15 is applied with consi erable initial compression and holds the inner friction blocks 12 in contact with the inclined faces on wedge 11.

The normally stationary friction plates 13 are generall rectangular in form with the corners notc ed out. The lugs 13' left between the notches are adapted to fitloosely between the ledges 22 and 23 of friction The outer ledges 23 also serve to limit 8 housing 10. The outer friction blocks 14 are interposed between said normally stationary friction plates and friction housing. The outer surface of each block 14 is cylindrically curved and the inner surface flat, in conformity with the shape of the surfaces respectively contacting therewith. Sufficient clearance intervenes between the top and bottom walls of the opening in the friction housing 10 and the outer friction blocks 14 to permit these outer friction blocks to rotate slightly about the axes of their curved faces, if necessary, to compensate for deviation from parallelism in the contacting surfaces of the normally stationary friction plates 13, inner friction blocks 12 or wedge 11. Lugs 14 on the outer friction blocks 14 and at intermediate portions ,of said blocks cooperate with ledges 23 on the outer portion of friction housing 10 to limit the outward movement of these blocks. The inner ends of the outer friction blocks 14 are in contact with the release spring 16 which resists the inward movement of these blocks when the gear is closed and returns them to normal position when the force acting upon the gear is relieved.

In the operation ofthe gear it is evident that the relative movement of the parts is the same whether the closure occurs by buffing or pulling. The action will be described for closure which occurs by buffing. Vhen force is transmitted from the coupler 6 to the follower 4, it is in turn transmitted to the wedge 11 and the outer friction blocks 14. The force on the wedge is resisted by the apphcation spring 15 acting. through the inner friction blocks 12. Part of the resultant pressure set up between the wedging surfaces is transmitted through the normally stationary friction plates 13 and outer friction blocks 14 to the friction housing 10. This pressure sets up friction between the inner friction blocks 12 and the normally stationary friction plates 13, and between the to the closure of the gear until the olearance has been taken up. Therefore, the initial movementis resisted only by the force of the application, spring 15 and release spring 16 and the friction between the outer friction blocks 14 and the friction housing 10. After the follower 4 has moved a distance equal to the clearance between the normally stationary friction plates 13 and the ledges 22 on the friction housing, friction on. both friction surfaces of each of the two normally stationary plates 13 acts to resist further movement.

As the draft gear is compressed, the inclination of the cylindrical surfaces in the friction housing 10 causes the wedge faces of the inner friction blocks 12 to approach. This causes the wedge 11 to move outwardly relatively to the inner friction blocks 12, setting up friction between the members, which increases the force acting to press the friction members together. The action as described can continue until the follower 4 comes in contact with the friction housing 10. The friction housing 10 and spring housing then cooperate to limit the movement of the follower and take force without any additional strain being transmitted to the springs or friction members.

\Vhen the force which has closed the gear is relieved, the springs 15 and 16 tend to restore the parts to normal positions. At the beginning, the outer friction blocks 14, normally stationary plates 13, and the inner frict-ion blocks 12 move as a unit until the normally stationary plates 13 come in contact with ledges 23 in the friction housing. Thus the only resistance to the initial movement is the friction between the outer friction blocks and the friction housing. This enables the parts to overcome the friction of rest and .causcs a slight impact which helps to free the friction surfaces when the normally stationary plates reach the limit of their movement in the friction housing. During the outward movement of the inner friction blocks 12 the distance between the wedging surfaces thereon increases. The relative movement thus set up between the inner friction blocks 12 and the wedge 11 increases the proportion of the force from the application spring 15 which is transmitted directly through the wedge 11 to the follower 4 and decreases the component which sets up pressure on the friction surfaces. The release of the friction members is facilitated by this action. The movement of the parts gear attains its normal length when the movement of the outer friction blocks 14 would be arrested by the engagement of lugs 14 with ledges 23, and the movement of the wedge 1l would be stopped by thelugs 11 thereon coming in contact with ledges 23in the friction housing,

The inner friction. blocks 12 are formed so that they will not come in contact with the release spring 16 in the normal operation of the gear. However, the corners of these blocks lap the release spring so that if the inner friction blocks stick during the release, the force of the release spring will come into action to assist in moving them after the release spring and outer friction blocks have moved a predeternlined distance in advance of the application spring 15 and the inner friction blocks 12. Y

The application spring 15 is adapted to compensate for wear in the friction members as this spring is under some compression when the gear is in the release position so that any wear on the friction surfaces would be taken up by outward movement of the inner friction blocks 12 caused by the application spring.

Changes may be made without departing from the invention.

Having thus described my invention, I claim:

1. A draft gear including a load-sustaining column member; relatively movable intercalated friction members supported by said column member, which is in frictional engagement with the adjacent intercalated members, the intercalated members adjacent the latter members being in frictional en gagement therewith; means for pressing said intercalated members and column memher into frictional engagement, where adjacent, some of the engaging pressure transmitting surfaces being curved to enable the elements carrying them to be in rocking relation to equalize pressure on these elements; and means for returning actuated members to released posit-ion upon relief of draft strains.

2. A draft gear including a load-sustaining column member; relatively movable intercalated friction members supported by said column member, which is in frictional engagement with the adjacent intercalated members, the intercalated members adjacent the latter members being in frictional engagement therewith; means, subject to draft strains, for setting up pressure on said friction members, engaging friction surfaces of said column and some of said members being curved to enable the elements carrying them to be in rocking relation to equalize pressure on these elements; and means forreturning the parts to a released position after draft stresses are relieved.

3. A draftgear including a load sustaining column member; relatively movable intercalated friction members supported by said column member, which is in frictional engagement with the adjacent intercalated members, the intercalated members adjacent the latter members being in frictional engagement therewith; means for pressing said intercalated members and column memher into frictional engagement, where adjacent, some of the engaging pressure transmitting surfaces being substantially cylindrical and coaxial to enable the elements carrying them to be in rocking relation to equalize pressure on these elements; and means for returning actuated members to released position upon relief of draft strains.

4. A draft gear including a load sustaining column member; relatively movable intercalated. friction members supported by said column member which is in frictional engagement with the adjacent intercalated members, the intercalated members adjacent the latter members being in frictional engagement therewith; means, subject to draft strains, for setting up pressure on said friction members, engaging friction surfaces 0f said column and some of said members being substantially cylindrical and coaxial to ena ble theelements carrying them to be in rocking relation to equalize pressure on these elements; and means for returning the parts to a released position after draft stresses are relieved.

5. A draft gear including a load sustaining column member; relatively movable intercalated friction members supported there by, each surface of two pairs of engaging pressure transmitting surfaces being curved to enable the elements carrying them to be in rocking relation to equalize pressure on these elements, each of these pairs of surfaces sloping with respect to the other; means for pressing the friction members into frictional engagement; and means for returning actuated members to released position upon relief of draft strains.

6. A draft gear including a load sustaining column member; relatively movable intercalated friction members supported thereby, two of which are respectively in frictional engagement with two surfaces of said column member; means, subject to draft strains, for setting up pressure on said friction members, engaging friction surfaces of said column and some of said members being curved to enable the elements carrying them to be in rocking relation to equalize pressure on these elements, each of these pairs of surfaces sloping with respect to the other; and means for returning the parts to a released position after draft stresses are relieved.

7. A draft gear including a load sustaining column member; relatively movable intercalated friction members supported thereby, each surface of two pairs of engaging pressure transmitting surfaces being substantially cylindrical, such surfaces of each pair being coaxial to enable the elements carrying them to be in rocking relation to equalize pressure on these elements, each of these pairs of surfaces sloping with respect to the other; means for pressing the friction members into frictional engagement; and.

means for returning actuated members to released position upon relief of draft strains.

8. A draft gear including a load susta ning column member; relatively movable 1ntercalated friction members supported thereby, two of which are respectively in frictional engagement with two surfaces of said column member; means, subject to draft strains, for setting up pressure on said friction members, engaging friction surfaces of said column and some of said members being substantially cylindrical and coaxial to enable the elements carrying them to be in rocking relation to equalize pressure on these elements, each of these pairs of surfaces sloping with respect to the other; and means for returning the parts to a released position after draft stresses are relieved.

9. A draft gear including av spring housing; a friction shell having cylindrical friction surfaces whose axes converge: ledges on the inner side of said friction shell; outer friction blocks adapted to move longitudinally on the cylindrical surfaces of said friction shell; friction plates in contact with said outer friction blocks and mounted between the ledges of said friction shell with capacity for limited relative movement; inner friction blocks between the outer friction blocks and in contact with said friction plates; a wedge in contact with said inner friction blocks having lugs cooperating with the aforesaid ledges for limiting its outward movement; a release spring in the spring housing acting on the outer friction blocks;

and an application spring within the release spring acting on the inner friction blocks.

10. A draft gear including a friction shell; relatively longitudinally movable intercalated friction members, including outer friction blocks each having one friction surface flat and an opposite friction surface cylindrical; lugs on said outer friction blocks cooperating with said shell to limit movement of said blocks; means for setting up pressure on said friction members in response to draft strains; and means for releasing said friction members.

11. A draft gear including a friction shell; relatively longitudinally movable intercalated friction members including outer friction blocks; lugs on intermediate parts of said outer friction blocks cooperating with an end portion of said shell to limit movement of said blocks on release but permitting movement during closure; means for setting up pressure on said friction members in response to draft strains; and means for releasing said friction members.

12. A draft gear including a friction shell;

friction members including outer friction blocks, inner friction blocks, and normally fixed plates between the outer and inner blocks; wcdging means, said inner friction blocks cooperating with the wedging means and moving toward each other during gear neaaa'ri closure; application means; and release means, the sides of said inner friction blocks extending to make contact with the releasing means in case the release means releases faster than the application means,

13. A draft gear including a friction shell; friction members including curved outer friction blocks, inner friction blocks and normally fixed plates between the inner and outer blocks; a central wedge cooperating with said inner friction blocks; an application spring acting on said inner friction blocks; and-a release spring acting on said outer friction blocks.

14. A draft gear including a load sustaining column member; relatively movable intercalated friction members supported by said column member, which is in frictional engagement with the adjacent intercalated members, the intercalated members adjacent the latter members being normally stationary with respect to said column member; means for pressing said intercalated members and column member into frictional engagement, where adjacent, some of the engaging pressure transmitting surfaces being curved to enable the elements carrying them to be in rocking relation to equalize pressure on these elements; and means for returning actuated members to released position upon relief of draft strains.

15. A draft gear including a friction shell: friction members including outer friction blocks. inner friction blocks, and normally fixed plates between the outer and inner blocks; wedging means interposed between said inner friction blocks and having a lug formation cooperating with said shell to limit the outward movement of the wedging means, said inner friction blocks cooperating with the wedging means; applica tion means; and release means.

16. A draft gear including a load sustaining column member; relatively movable intercalated friction members supported thereby, some of the engaging pressure transmitting surfaces of the aforesaid members being curved to enable friction members to' be in rocking relation to equalize pressure thereon; application spring means; and release spring means independent of the application spring means.

In witness whereof, I hereunto subscribe my name.

ALBERT F. STUEBING. 

